Shockproof connector device



AAPY-il 29, 1947 J. F. oBRlEN Erm. 2,419,585

SHOCK-PROOF CONNECTOR DEVICE Filed Juge s, 1944 `2 shuts-sheet 1 ,CD 15 ,Q 1a @61511. r @Q/OZ. 3Q

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I 37 l L 35 BYE |21. s. B YNTON 17 3b 16 uw u y RNEY April 29,1947. J. F. o'BRlEN ErAL SHOCK-PROOF CNNVECTOR DEVCE Filed June 3, 1944 2 sheets-sheet 2 INVENTORS JosEDH F. O'BRIEN BY EAL s. BOYNTON Patented Apr. 29, 1947 snocxrnoor coNNEcroa nsvrcc Joseph F. OBrlen, Jersey City, and Earl S. Boynton, East Orange, N. J., assignors to John B. Pierce Foundation, New York, N. Y., a corporation of New York lApplication June 3, 1944, Serial No. 538,642

18 Claims. l

The present invention relates to improvements in electrical plug connecting devices.

An object of the invention is to provide an improved connecting device such as a receptacle, or outlet or like connecting device for an electrical plug or like electrical connection member having iiat face terminals the edges of which are rectilinear, wherein the metal elements accessible through the openings of such device, at the stage of non-association with the plug, are dead, thus insuring safety against tampering or other unwise act; such as a child or other person inserting a hairpin or wire within such opening.

Another object of the invention is to provide an improved connector device applicable for electrically connecting the conductor or conductors leading to an electrical device, whereby the electrical circuit through the metallic elements of such connector device accessible from the exterior of such electrical device is automatically broken upon disconnecting a conventional electrical plug or equivalent with respect to such connector device.

Such arrangement obviates the need of a switch either in the immediate circuit of the electrical device or in association with the connector device, and also precludes arcing upon separation of the terminals of the electrical plug with respect to the metallic elements of the connector device accessible exteriorly thereof.

More specifically, pursuant to the invention, the receptacle, outlet orV like connecting device associated with an electrical plug or like electrical connection member having flat face terminals the edges of which are rectilinear, is provided with a set of contact elements which are directly connected with the conductors leading from a source of electrical current, such contact elements being designated herein as live contact elements; associated with such live contact elements, respectively, are circuit-closing elements having flat faces which elements are suitably spaced relative to such live contact elements at the stage of non-insertion of the plug and are accordingly dead Such circuit-closing elements are provided with iiat faces which are located in substantial alignment with the openings of the receptacle, outlet or like connect- (ci. 20o-51.09)

r"live contact elements upon Withdrawal of the terminals of the plug or the like.

A further feature of preferred embodiments of the invention resides in the formation or arrangement of the contact-making' elements whereby a rm mechanical grip upon the flat face terminals of the plug or the like is secured,

thereby insuring maintenance of positioning of the plug at the stage of insertion, thereby safeguarding against loose electrical connection or accidental disconnection.

Among the structural and functional features of preferred embodiments of the invention are simplicity of assembly of the component parts, with attendant low cost of manufacture, certainty of operation under normal use, maximum surface contact engagement of the respective electrical conducting parts, and avoidance of joints in the -path of the electric current under current-now conditions.

In the accompanying drawings:

Fig. l is a central sectional elevation of a preferred type of embodiment of the invention in association with a conventional electrical plug having nat-faced terminals the edges of which are rectilinear, the body of such plug being shown in elevation. 'Ihis view illustrates the flatfaced terminals of the plug in full inserted position and the contact-making elements in engagement with the live contact terminals. Fig. 1 illustrates the embodiment in the form of a, Wall receptacle.

Fig. 2 is a central sectional view similar to that of Fig. 1, showing the plug in partly inserted position relative to the contact-making elements, at which state the contact-making elements are dead Y Fig. 3 is a plan View of another embodiment of the invention, comprising a double receptacle. A conventional plug is shown in full inserted position and the circuit-closing elements in closedcircuitposition with respect to one of the receptacles.

Fig. 4 is a central sectional view of Fig. 3.

Fig. 5 is a rear view of the embodiment shown ,y

in Figs. 3 and 4.

Fig. 6 is a longitudinal sectional view of the".

the embodiment illustrated ln Figs. 3 through 6.

Referring to the embodiment shown in Figs. 1 and 2, the electrical plug l0 is shown of conventional construction having flat-faced terminals the edges of which are rectilinear; asis apparent, any suitable type of electrical plug having flatfaced terminals the edges of which are rectilinear, is applicable in conjunction with the variant is of the wall-receptacle type, indicated generally I3, serving as an illustration of al1 types of electrical connecting devices applicable under the invention. Specifically, as is illustrated in Figs. 1 and 2, the receptacle box is indicated at I4, which may be located in a suitable opening I formed in a wall or partition, indicated at I6, and provided with a face-plate I1,

Such receptacle is shown comprising a hollow housing I8, preferably of electrical insulating material, its face member I9 having the conventional openings 20, 2|, for the reception of the terminals I I, I2 of a suitable electrical plug. The

face member I9 may include as an integral portion thereof a partition 22 serving to eiectually subdivide the hollow interior of the housing I8. Theface member I9 and its thus combined partition 22 may be molded integrally with the side walls of the housing, in which construction the bottom I8a is molded separately and these parts assembled by any suitablemeans, such as fastening screws 23. Or, as shown in Figs. 1 and 2, the bottom I8a may be molded integrally with the side of the housing and the face member I9 molded separately, and secured'similarly in assembled position.

The contact-making elementsare indicated at 25, 26 and are shown of a attened general S- shape. Preferably, suchcontact-making elements are located to be self-supporting and be maintained in position within the respective subcompartments of the housing I8. The contact terminals are indicated at 21, 28, and as shown in Figs. 1 and 2 are in the form of flat-faced strips of brass which are secured to the inner faces of opposing side walls of the housing I8,

through which walls project their binding posts 29, 30, the latter being arranged for good electrical connection with suitable electrical feed conductors, indicated at 3 I, 32.

The contact-making elements 25, 26, and the contact terminals 21, 28, are of electrically conducting material, preferably of resilient metal. The contact-making elements 25, 26 are desirably of resilient metallic material.

' As appears in Fig. 2, at the stage of non-insertion of the terminals of the plug, or partial insertion of the plug terminals Il, I2, the contact-making elements 25, 26 are suitably spaced with respect to the contact terminals 21, 28, to insure that the contact-making elements 25, 26 are dead To obtain such objective and to effect the stated self-support and maintenance in self-positioning, it is desirable to lodge the contact-making elements at their respective bend portions indicated 25a and 26a in grooves or the like, indicated at I8b, which may be formed integral with or secured to the bottom I8a of the housing I8. Such self-support and selfmaintenance in position may be further effected by the provision of the flanges Illa formed integral or attached to the inner face of the face member I9. Such construction is advantageous in that the contact-making elements 25, 26 may be initially loosely placed respectively relative to the anges I9a, I9a, and the grooves 25a and 26a', and upon tightening the screws 23, or equivalent, the contact-making elements 25, 26 are properly located within the housing I8.,

Assuming the terminals II, I2 of the plug I0 are positioned partially within the outlet openings, as is indicated in Fig. 2, whereat their 'extremities ltouch the contact-making elements 25,

26, now upon applying pressure through the body 'l of the plug to force its terminals II, I2 into the bight between the arcuate bends of the flattened S-shaped elements,v their free ends 25o, 26C are displaced toward and into electrical engagement with the juxtaposed portions 21a, 28a of the terminals 21, 28, thus eilecting circuit-closing, namely, say, from. the feed conductor 3I through the binding post 29, thence its contact terminal 21, thence the therewith associated contact-making element 25, to the plug terminal II, and from the plug terminal I2 to its associated contact-mak.. ing element 2li, thence the associated contact terminal 28, its binding post 30 and iinally to the feed conductor 32,. as shown in Fig. 1.

Upon withdrawal of the plug III and its terminals II, vI2, to the position, say, indicated in Fig. 2, the displaceable portions of the contactmaking elements 25, 26, by reason of their resiliency, spring back to their respective .dead positions. To safeguard against pitting due to arcing of current, it is desirable to provide the respective contact-engaging ,portions of the contact-making elements and the contact terminals with silver or like facing, as by inlaying their respective portions with such protective metal. as

is indicated at 25e, 26e, and 21a, 28a.

The terminals of conventional electrical plugs 'are usually each equipped with a perforation within the body of the terminal adjacent its free end, such as are indicatedat Ila, I2a, respecfording additional means for retaining the plugy terminals against unintentional displacement. Such protuberance`s\s\erve also, at the stage of initial withdrawal of`\tl '1e plug terminals, to cock the free end portioiis25e, 26c, of the contact-making elements, and thus"`^enhancewthe speed of circuit-breaking between the contactmaking elements25, 26, and their respective contact terminals 21, 2`8-,\approximately at the stage when the tips of the plugterminals are moved out of contact with the displaceable portions of the contact-making elements. g

As shown in the drawings, it is advantageous to form the contact-making elements of flat stock and to arrange the contact-making elements within the housing to be engaged by the flat faces of the plug terminals, thus aifording Iace-to-face engagement with attendant friction between the stated parts. Such face-to-face engagement is illustrated in Fig. 2'at the stage of initial engagement of the lower portion of each plug terminal with the displaceable portion of its associated contact-making element. Upon movement to the nal inserted position of each plug terminal, as illustrated in Fig. 1, the fiat face of the end of such plug terminal is brought into face-toface engagement with the displaceable part of its associated contact-making element, thus affording double face-to-face engagement during the stage of current ow.

Figs 3 through 6 illustrate an embodiment of the invention as applied to a double outlet or double convenience receptacle and the parts cor- 5 responding'to those shown in Figs. 1 and 2 are designatedby like reference characters,

Suchdouble outlet or receptacle is conveniently sec'uredwithinv an outlet box 35 as by means of a conventional strap or equivalent having securing flanges, designated at 36, 36, for appropriate 'attachment as by screws 31.

Itk is'fobserved that the housing of the double outlet or receptacle is illustrated as having its face member I9 molded integrally with its side walls and its bottom 18a molded separately, and theassembly secured by screws 23.

It`i`s"desirable 'to form the contact terminals of the double outlet or receptacle type of a single strip of metaL-as illustrated in Fig. '7, with reference to the double contact terminal 28. As shown individually in Fig. '7, and in assembly in Figl 6, each double terminal 28, and likewise the double terminal 21, may be bent outwardly, as indicated at 33, to protrude through suitable openings 34, 34, in the housing I8, thus affording secured lodgement of the contacts 21, 28, within the housing; Such lodgement may be enhanced by notching the contacts to form ears or extensions, as isi indicated at 38, see also Fig. 6, and

seating such ears or extensions Within suitable slots, indicated at 39, which may be molded or formed Within the housing I8.

Also, the contact-making elements 25, 26 may each be provided with the oppos'itely projecting ears, such ears 26e, 26e, for the contact-making element 26 being shown in Fig. 7; such ears are lodged within notches 40, molded or formed within the housing body I8. Fig. 6 shows the ears 25e of thelelement 25 and the ears 26e of the 'i element 26, with reference to the double embodim nt, and similar ears may be provided in theV si lgle receptacle embodiment illustrated in Figs. 1 and 2.

s show'n in Figs. 1 through '7, each contactmaking'element comprises a part which is lodged within the housing to be stationary in relation QQ!" to, as above set out, and another portion' is displaceable relative to its lodged por` tiony the displaceable portion being connected with such lodged portion by a reentrant or equivalent formation, the reentrant portion being positioned to be in substantial alinement with an Yopening in the receptacle housing whereby upon initial positioning of the free kend of a plug terminal within a receptacle opening, such free end engages such displaceable portion in leverage relation and upon applying force through the body of the plug, the plug terminal displaces under leverage such displaceable portion to eiTect good electrical engagement of its free end with the contact of the receptacle. Accordingly, each plug terminal serves not alone the conventional function of conduction at the stage of current flow but also to positively eiect and maintain closure of the electrical circuit.

It is apparent that the invention is applicable for receptacles', outlets and other connector devices adapted fo'r association with plugs having three or more terminals, or having but a single As is apparent, the contact-making element K pursuant to the invention comprises a portion or part constructed or arranged to be stationary relative to the housing or equivalent of a receptacle, outlet, or other connector device, and a portion or part of electrically conductive material which is displaceable relative to the previously named portion or part, such displaceable portion or part being electrically insulated with respect to the electrical contact of such connector device at the stage of non-now of the electrical current, but displaceable by the terminal of a plug or equivalent to effect electrical engagement with such electrical contact.

' It is also apparent thatv it is advantageous to construct the contact-making element of electrically conducting material and to provide resiliency with respect to its displaceable portion or part."

Y It will be observed with respect to receptacles, outlets, and other connector devices having two l or more electrical contacts and therewith associated contact-making elements, the latter having their displaceable portions or parts opposingly related with respect to one another, as herein set forth, that the forces of reaction brought about by the leverage action upon the displaceable portions or parts of the respective contact-making elements upon insertion of the terminals of a plug, are counter-balanced with respect to the plug terminals by the stationary portions or `parts oi lthe contact-making ele- 'ments, thus facilitating the operation of inserting'and seating the plug terminals in currentflow position.

From the above, it is apparent thatembodiments of the invention possess simplicity of construction, favorable for low-cost production, minimum heating loss and consequent maximum current .flow under circuit-closing condition, ruggedness of construction, insuring long life, and

other advantages, as will be readily understood by these skilled in the art.

What we claim is:

l.. For use with a conventional electrical plug or like connection member having nat-faced ter-` minals, the edges of which are rectilinear, connecting means comprising a hollow casing provided with openingsffor the reception of the fiatfaced rectilinearly-edgcd terminals of the plug,

live electrical elements adapted to be connected.

electrical elements.

terminal, as in a simple make-and-break conf nector attachment. The invention is also applicable for two-pole receptacles, outlets or other 2. For use with a conventional electrical plug or like connection member having flat-faced terminals, the edges of which are rectilinear, connecting means comprising a hollow casing provided with openings for the reception of thefiatfaced rectilinearly-edged terminals of the plug. live electrical terminals adapted to be connected to electrical conductors, and circuit-closing element-s having viiat faces normally insulated fromv said live electrical terminals and arranged to be brought, into electrical engagement respectively.

faced rectilinearly-edged terminals of the plug, live electrical terminals adapted to be connected to electrical conductors, and re-entrantly formed resilient circuit closing elements disposed within the casing and normally insulated from said live electrical terminals and having at faces at their re-entrant formations positioned to be engaged by the terminals of the plug and effect electrical engagement of said contact-making elements with said live electrical terminals.

4. A connector device comprising a hollow housing, said housing being provided with an opening for the reception of the terminal of a plug, an electrical contact insulatedly mounted within said housing, and circuit-closing means within said housing electrically insulated with respect to said electrical contact at the stage of non-flow of electrical current and arranged to effect circuit closing relative to said electrical contact upon insertion through said opening of the plug terminal, said circuit-closing means including an element bent upon itself and mounted within said hollow housing at its bend, said element having a fiat face accessible through the opening of said housing for engagement therewith by the plug terminal.

5. A connector device comprising a hollow housing, said housing being provided with an opening for the reception of the terminal of a plug, an electrical contact insulatedly mounted within said housing, and resilient circuit-closing means within said housing electrically insulated with respect to said electrical contact at the stage of non-flow of electrical current and arranged to eiect circuit closing relative to electrical contact upon insertion through said opening of the plug terminal, said resilient circuit-closing means including a part bent upon itself and mounted within said hollow housing at its bend, said element having a flat face accessible through the opening of said hollow housing for engagement therewith by the plug terminal.

6. A connector device comprising a hollow housing, said housing being provided with a plurality of openings for the reception of terminals of a plug or equivalent, electrical contacts insulatedly mounted within said housing, resilient circuit-closing means within said housing elec-l trically insulated with respect to said electrical contacts respectively at the stage of non-flow of electrical current and arranged to effect circuitclosing relative to said electrical contacts respec tively upon insertion through said openings of the terminals of said plug, said resilient circuitclosing means including a set of elements corresponding to the number of terminals of the plug, each being of wholly electrically conducting material, a part of which is bent upon itself and engaging an interior wall of said hollow housing at its bend, said elements having at faces respectively accessible through the openings of said hollow housing for engagement therewith respectively by the plug terminals.

7. A connector device comprising a hollow housing, said housing being provided with a plurality of openings for the reception of terminals of a plug or equivalent, electrical contacts inthe terminals of saidplug, said resilient` circuitclosing means including elements of wholly electrically conducting material corresponding in number to the number of the terminals of the plus and disposed within said casing in opposing relationship with respect to said electrical contacts, said resilient circuit-closing means including a set of elements corresponding to the number of terminals of the plug, each being of wholly electrically conducting material, a part of which is bent upon itself and engaging an interior wall of said hollow housing at its bend, said elements having nat faces respectively accessible through the openings of said hollow housing for engagement therewith respectively by the plug terminals.

8. A connector device comprising a hollow housing, said housing being provided with a plurality of openings for the reception of terminals of a plug or equivalent, electrical contacts insulatedly mounted within said housing, and resiliency-provided circuit-closing means within said housing electrically insulated with respect to said electrical contacts respectively at the stage of noniiow of electrical current and arranged to effect circuit-closing relative to said electrical contacts respectively upon insertion through said openings of the terminals of such plug. said resiliency-provided circuit-closing means including elements of resilient electrically conducting material corresponding in number to that of the terminals of the plug, said elements having reversed bends respectively, and means for mounting said elements within said hollow housing to present face portions of said elements accessible through said openings of said hollow housing accessible to the plug terminals respectively for engagement therewith.

9. A connector device comprising a hollow housing, said housing being provided with a plurality of openings for the reception of terminals of a plug or equivalent, electrical contacts insulatedly mounted lwithin said housing and resiliency-provided circuit-closing means within said housing electrically insulated with respect to said electrical contacts respectively at the stage of non-ilow of electrical current and arranged to eflect circuit-closing relative to said eelctrical contacts re- I spectively upon insertion through said openings of the terminals of such plug, said resiliency-provided circuit-closing means being disposed within said housing in opposing relationship to said electrical contacts respectively, said resiliency-provided circuit-closing means including elements of resilient electrically conducting material corresponding in number to that of the terminals of the plug, said elements having reversed bends respectively, and means for freely mounting said elements within said hollow housing to present face portions of said elements accessible through said openings of said hollow housing accessible to the plug terminals respectively for engagement therewith. I

10. For use with a conventional electrical plug or like connection member having nat-faced terminals, the edges of which are rectilinear, an outlet or receptacle comprising-a hollow body, electrical contacts insulatedly mounted in said body and arranged to be connected with feed conductors; said housing being provided with openings for the reception of the terminals of a plug; and elements disposed Within said housing normally out of electrical connection with said contacts, said elements having flat faces arranged to be respectively engaged by the terminals of such plug inserted through said openings and to be forced' by 9 the plug terminals into electrical connection with said contacts.

11. For use with a conventional electrical plug or like connection member having flat-faced terminals, the edges of whichare rectilinear, an outlet or receptacle comprising a hollow body, electrical contacts insulatedly mounted in said body and arranged to be connected with feed conductors; said housing being provided with openings for the reception of the terminalsof a plug; and

resiliency-provided elements disposed within said housing normally out of electrical co-nnection with said contacts, said elements having ilat faces arranged to be respectively engaged by the terminals of such plug inserted through said openings and to be forced by the plug terminals into electrical connection with said contacts.

12. For use with a conventional electrical plug or like connection member having fiat-faced terminals, the edges of which are rectilinear, an outlet or receptacle comprising a hollow body, electrical contacts insulatedly mounted in said body and arranged to be connected with feed conductors; said housing being provided with openings f or the reception of the terminals of a plug; and resiliency-provided elements disposed within said housing normally out of electrical connection with said contacts, said elements having fiat faces arranged to be respectively engaged by the terminals of such plug inserted through said openings.

and to be forced by the plug terminals into electrical connection with said contacts, said resiliency-provided elements being disposed within said housing in opposing relation to said electrical contacts respectively.

13. A connector device comprising a hollow housing provided with mutually spaced openings, contacts for connection with the leads of a source of electrical energy mounted within said hollow body at locations inaccessible through said openings, and circuit-closing means disposed within said hollow housing and including elements oi' resilient electrically conducting material, each of said elements having reversely bent parts, means for mounting each said element to present)` the bight between its contiguous bent portions in.

alignment with one of said openings, said elements corresponding in number to that of said openings, whereby upon insertion of an electrical plug having terminals corresponding in numf ber and mutual spacing to said openings, the plug terminals enter the respective bights of said elements to displace bent portions Yof said elements to respectively engage said source-connected contacts. l

14. A connector device comprising la hollow housing provided with mutually spaced openings, contacts for connection with the leads of a source of electrical energy mounted within said hollow body at locations inaccessible through said openings, and circuit-closing means disposed within said hollow housing and including elements of resilient electrically conducting material, each of said elements having reversely bent parts, means for mounting each said element at its bend and to present the bight between its contiguous bent portions in alignment with one of said openings, said elements corresponding in number to that of said openings, whereby upon insertion of an electrical plug having terminals corresponding in number and mutual spacing to said openings, the plug terminals enter the respective bights of said elements to displace bent portions of said eleycontacts for connection with the leads of a source of electrical energy mounted within said hollow body at locations inaccessible through said openings and circuit-closing means disposed within said hollow housing and including elements of resilient electrically conducting material, each of said elements having reversely bent parts, means for mounting each said element freely at its bend and to present the bight between its contiguous bent portions in alignment with one of said openings, said elements corresponding in number to that of said openings, whereby upon insertion of an electrical plug having terminalscorresponding in number and mutual spacing to said openings, the plug terminals enter the respective bights of said elements to displace bent portions of said elements to respectively engage said source-connected contacts.

16. A connectordevice for association with a conventional electrical plug or like connection member having flat-faced terminals, said connector device comprising a hollow housing provided with openings for the reception of the terminals of such connection member, mutually spaced electrical contacts insulatedly mounted within said housing and arranged for connection with an electrical supply, and circuit-closingI elements insulatedly mounted within said housin'g and normally out of engagement with said mutually spaced electrical contacts respectively, said circuit-closing elements each including a resiliently mounted part, said resiliently mounted parts being provided with ilat faces respectively disposed in substantial alignment with the paths of movement of the terminals of such connection member, and constructed upon face-to-face engagement with the flat faces of such terminals to be displaced respectively' toward said con-J tacts and in engageme t therewith, thereby closing the electrical circuit through the connector device. l,/ v f 17. LA connector device as dened by claim 16 in which said circuit-closing elements are each of flattened S-shape and its said resiliently mounted part is oi arcuateA formation having its frel end projecting in -the 'direction of its said ass ciated contact. y l

18. A connector device as defined by claim 16 in which said circuit-closing elements are each of iiattened S-shape and each provided with a protuberance forming with its said resiliently mounted part a bight, said bights of the respective circuit-closing elements being disposed in substantial alignment with the respective'paths of movement of the terminals of such connection member. I

JOSEPH F. OBRIEN. EARL S. ,BOYNTON.

REFERENoEs CITED The following references are of record in the le of this patent: v

UNITED STATES PA'I'ENTs Freeman f... Oct. 16, 1923 

